AbstractIn this paper we propose a new fault location algorithm for power transmission lines based on one terminal voltage and current data. A distributed time domain model of the line is used as a basis for algorithm development. The suggested technique only takes advantage of post‐fault voltage and current samples taken at one end of the line and does not require filtering of DC offset and high‐frequency components of the recorded signals, which are present during transient conditions. Another advantage of the proposed method is the application of a very narrow window of data i. e. less than 1/4 of a cycle. The paper also proposes two different algorithms for lossless and lossy line models. Computer simulations approved the accuracy of the proposed methods.